What still catches my eye is the order of magnitude difference between CA and the NY-NJ area. NY and NJ have major international airports. So, too, does CA. NY and NJ have a lot of companies that do business in China, including people going to and from China. So, too, does CA.
My WAG is that the EU's delay in shutting down China travel resulted in people being infected in EuroLand and then bringing it back to NY-NJ more than CA.